Abstract

OSA’s 93^rd Annual Meeting - San José, CA, USA, Frontiers in Optics (FiO) 2009/Laser Science (LS) 25th Conference Optics for Renewable Energy Keynote Speaker: FMB1, Optics of Solar Cells, Greg P. Smestad, Monday, October 12, from 1:30 PM - 2:15 PM What are Systems? A system is a group of interacting, interrelated, and interdependent components that form a complex and unified whole. Systems Thinking is a framework that is based on the belief that the component parts of a system can best be understood in the context of relationships between components and with other systems, rather than in isolation. Solar Cells can be simple, but they can also be complex. Band Diagrams are useful, but recombination determines efficiency. Diode Equation System Properties Energy, material and information are among the different elements that comprise the system and these flow o to and from the surrounding environment via semi-permeable membranes, barriers or boundaries. Senge Diagram Photovoltaic Cell The Planck Equation describes solar radiation, but absorptivity describes what is absorbed. E. Sacks/MIT/1366 Technologies; Veeco Instrument Inc. Optical Profiler Generalized Planck Equation Planck Describes Rad. Recombination Define and Integrate Detailed Balance Diode Equation emerges from Planck Radiative Recombination Detailed Balance Efficiencies All from a Systems Approach to a Photovoltaic Cell A Solar Cell is a System The performance of solar cells is determined by how its materials absorb, reflect and even emit light. Want More on this Optical Perspective? Look for publications by: Shockley and Queisser Harald Ries P. Wuerfel (Würfel) www.nrel.gov/pv/measurements/computational_modeling.html and (yes) Greg P. Smestad G. Smestad, "Absorptivity as a predictor of the photoluminescence spectra of silicon solar cells and photosynthesis," Solar Energy Materials and Solar Cells, 38, 57, 1995. What else is it good for? scientific, engineered, human, or conceptual. PV Module Systems K. R. McIntosh, R. M. Swanson and J. E. Cotter, A Simple Ray Tracer to Compute the Optical Concentration of Photovoltaic Modules, Prog. Photovolt: Res. Appl. 2006; 14:167-177.Residential Systems PV Systems Connected to Grid SEGIS Dynamics needs Real-Time Data Solar Resource Monitoring PV Experience Curve Senge Diagram — Representation of System-Focused Solar Industry Development Senge Diagram — System-Focused Solar Industry Development Powering the Solar Innovation Engine Interconnected systems reinforce the innovation process. Positive Reinforcement spins the wheels faster! Feedback loops create virtuous cycles. Conclusions Solar Cells can be viewed from a purely optical perspective. Solar Energy R&D and Industry Drivers should be considered in the context of Systems Thinking. Such perspectives lead to a multidisciplinary, collaborative approach. This can reduce the product development interval and facilitate technology transfer to more rapidly spin the Solar Innovation Engine. Thank you Solar Energy Materials and Solar Cells Sol Ideas Technology Development OSA Science Educators Day Questions & Answers How does the Systems Approach in the Senge Diagram relate to OSA? OSA is one of many organizations that feed in to the policy and supply chain aspects of PV. One recommendation from the approach is collaboration, coordination and integration between such organizations. Questions & Answers With PV technologies and systems so diverse, how can the Systems Approach be used? All installed PV systems must adhere to national and international standards of performance, longevity and stability. Earlier PV technologies can set the stage for new solar technologies as they enter the market. Questions & Answers How was the approach developed? It was developed by several reviewers for DOE, but does not represent the views of the U.S. Department of Energy. We developed this analysis by substantial participation in the DOE Solar Energy Technologies Program’s 2009 Annual Program Peer Review held in March, 2009. More information is available (in the Past Meetings section) on the DOE website at: www1.eere.energy.gov/solar/review_meeting/

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